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3,4-二氟苯腈是一种重要的中间体,目前合成方法有采用3,4-二氯苯腈为原料,通相转移催化制备,由此建立了反应过程中同时测定3,4-二氟苯腈和3,4-二氯苯腈的高效液相色谱定量分析方法。以C18色谱柱为分离柱,70%甲醇水溶液为流动相;紫外检测波长设定为210 nm,可以实现反应液中这两种物质的同时检测。3,4-二氟苯腈和3,4-二氯苯腈的最低检出浓度分别为0.04和0.03μg/m L,线性范围分别为0.1~500和0.1~100μg/m L,方法的回收率为92%~106%,相对标准偏差(RSD)为1.0%~2.5%。此外,进一步考察C18 SPE小柱富集微量3,4-二氯苯腈的方法,可以实现3,4-二氟苯腈粗品中3,4-二氯苯腈的含量分析,自制的3,4-二氟苯腈样品中,3,4-二氯苯腈的含量为0.2%,加标回收率为97%。 相似文献
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以L -薄荷醇和 1,2 -环氧 - 3-氯丙烷等为原料 ,经取代、环氧化、水解等一系列反应合成新型凉味剂L -薄荷氧基丙二醇 相似文献
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以2-腈基-5-溴吡啶、三异丙基硼酸酯和正丁基锂为原料,用改良的Li—Br交换反应制备2-腈基-5-吡啶硼酸的方法,收率75%。其频那醇酯也方便地以2-腈基-5-吡啶硼酸和频那醇在甲苯中通过共沸脱水制备,收率81%。 相似文献
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2,5-二甲基对苯二甲腈α-位溴代反应 总被引:2,自引:1,他引:1
用N-溴代丁二酰亚胺(NBS)作溴化剂,以2,5-二甲基对苯二甲腈为原料,合成了目标化合物2,5-二溴甲基对苯二甲腈。用正交设计实验对影响2,5-二甲基对苯二甲腈生成2,5-二溴甲基对苯二甲腈的溴代反应条件进行了考察,最佳反应条件为:n(2,5-二甲基对苯二甲腈)∶n(NBS)=1∶2.1,反应温度80℃,2,5-二甲基对苯二甲腈浓度0.1 mol/L,反应时间16 h,产率可达31.4%。溴代粗品经反相柱色谱分离〔洗脱液:V(甲醇)∶V(水)=70∶30〕,洗脱组分分别是2-甲基-5-溴甲基对苯二甲腈、2,5-二溴甲基对苯二甲腈、2-甲基-5-(1,1-二溴)甲基对苯二甲腈与2-溴甲基-5-(1,1-二溴)甲基对苯二甲腈。 相似文献
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L-乳酸薄荷酯的合成及其在个人护理用品中的应用研究 总被引:1,自引:0,他引:1
以发酵乳酸和天然薄荷醇为主要原料用直接酯化法合成了乳酸薄荷酯,讨论了合成过程中带水剂的选择、投料配比、反应温度和反应时间对反应转化率的影响.实验结果表明,以四氯化碳为带水剂,m(乳酸):m(薄荷醇)=1.2:1,110℃反应3 h,薄荷醇对乳酸薄荷酯反应转化率可达75.5%.产品经减压蒸馏、重结晶处理后质量分数达99.6%.将其作为清凉剂应用于沐浴露、护肤乳液、爽身粉等个人护理化学品的配方中,并与传统清凉剂薄荷脑进行了性能对比研究.结果表明此产品应用于个人护理用品中,在人皮肤上的清凉作用和感觉方面与薄荷脑相比较更为温和而持久. 相似文献
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Xulin Yang Yingqing Zhan Jian Yang Hailong Tang Fanbing Meng Jiachun Zhong Rui Zhao Xiaobo Liu 《Polymer International》2012,61(6):880-887
In this study, novel nitrile functionalized graphene (GN‐nitrile)/poly(arylene ether nitrile) (PEN) nanocomposites were prepared by an easy solution‐casting method and investigated for the effect of surface modification on the dielectric, mechanical and thermal properties. Graphene (GN) was first functionalized by introduction of nitrile groups onto the GN plane, which was confirmed by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, thermogravimetric analysis and dispersibility research. Compared with pure GN, the grafted nitrile groups on the GN‐nitrile can interact with nitrile groups in PEN and lead to flat but better dispersion and stronger adhesion in/to the PEN matrix. Consequently, GN‐nitrile had a more significant enhancement effect on the properties of PEN. The dielectric constant of the PEN/GN‐nitrile nanocomposite with 5 wt% GN‐nitrile reaches 11.5 at 100 Hz, which is much larger than that of the pure PEN matrix (3.1). Meanwhile, dielectric loss is quite small and stable and the dielectric properties showed little frequency dependence. For 5 wt% GN‐nitrile reinforced PEN composites, increases of 17.6% in tensile strength, 26.4% in tensile modulus and 21 °C in Td5% were obtained. All PEN/GN‐nitrile nanocomposite films can stand high temperature, up to 480 °C. Hence, novel dielectric PEN/GN‐nitrile nanocomposite films with excellent mechanical and thermal properties can be used as dielectric materials under some critical circumstances such as high wear and temperature. Copyright © 2012 Society of Chemical Industry 相似文献
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《国际聚合物材料杂志》2012,61(11):1041-1050
Mechanical properties and morphology of blends of polystyrene and finely powdered (uncrosslinked and crosslinked) nitrile rubber were studied with special reference to the effect of blend ratio. Blends were prepared by melt mixing polystyrene and nitrile rubber in an internal mixer at 180°C in the composition range of 0–20 wt% nitrile rubber. The tensile stress/strain properties and impact strength of the polystyrene/nitrile rubber blends were determined using injection molded test specimens. In comparison to the blends with uncrosslinked nitrile rubber, blends with crosslinked nitrile rubber showed higher tensile strength, elongation at break, Young's modulus, impact strength, flexural strength, and flexural modulus. The enhanced adhesion between the dispersed nitrile rubber phase and the polystyrene matrix results in an increase in mechanical properties. Scanning electron micrographs of the fractured surfaces confirm the enhancement in mechanical properties. 相似文献
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氢化丁腈橡胶具有良好的耐油性和耐氧性,广泛应用于汽车和石油行业,通过丁腈橡胶溶液均相催化加氢制得,采用铑类和钯类均相催化剂。考察不同溶剂、催化剂及m(Ru)∶m(丁腈橡胶)对丁腈橡胶加氢的影响。采用红外光谱法和核磁法对氢化丁腈橡胶的结构进行分析,筛选出价廉、活性高和选择性高的催化剂。结果表明,在丁腈橡胶加氢反应中,丁酮可作为溶剂,Ru(PPh3)3Cl2催化剂具有高活性和高选择性。在丁酮200 m L、丁腈橡胶5 g、Ru(PPh3)3Cl2催化剂、m(Ru)∶m(丁腈橡胶)=0.000 20∶1、反应温度140℃、氢压8.0 MPa和反应时间4 h条件下,加氢度和选择性均达到100%,具有与Rh(PPh3)3Cl相当的催化性能。 相似文献
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丁腈橡胶作为硝酸异丙酯的密封材料,常常会发生硝酸异丙酯的渗漏挥发现象。为选择新的橡胶代替丁腈橡胶密封硝酸异丙酯,本文制备了丁腈橡胶与三元乙丙橡胶试样,测试经溶胀后丁腈橡胶与三元乙丙橡胶的质量与体积变化率、组织结构、表面形貌、力学性能,并对比了丁腈橡胶与三元乙丙橡胶溶胀后的性能。结果表明:丁腈橡胶与三元乙丙橡胶在硝酸异丙酯中溶胀后各方面性能均有所下降,但是三元乙丙橡胶溶胀后的性能要强于丁腈橡胶,显示出更好的耐硝酸异丙酯性能,建议使用三元乙丙橡胶并喷涂酚醛树脂液体密封胶密封硝酸异丙酯。 相似文献
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Jawed Asrar 《应用聚合物科学杂志》1993,47(2):289-293
This paper describes the polymerization and the copolymerization of dicyclopentadiene and norbornene nitrile by metathesis polymerization. It is found that the metathesis polymerization of dicyclopentadiene, which is very fast and exothermic, can be controlled by the addition of norbornene nitrile. Though the norbornene nitrile delays the polymerization at room temperature, at high temperatures, because of the presence of nitrile group, polymerization is accomplished in reaction injection molding time. Physical and mechanical properties of the polymers and copolymers are described. © 1993 John Wiley & Sons, Inc. 相似文献